Do you know that right now you are on a website that has a modern version of Romeo and Juliet that runs parallel to the original? Added to this, many of the archaic words are underlined in red in the original text. All that you need do is take your mouse arrow over these words and the modern meaning of the word will appear for your convenience. For example, in Act I the word collier is used in the second line of Scene 1. Its meaning is revealed by moving the arrow so that people who move coals appears.
Below is the site you need: